Impregnation of leather and products thereof



Patented Sept. 21, 1937 I v I i Q UNITED STATES PATENT OFFICE IMPREGNATION OF LEATHER AND PRODUCTS THEREOF I Per K. Frolich, Roselle, N. J., asslgnor to Standard, 1 Oil Development Company, a corporation of Delaware r No Drawing. Application January 3, 193 3,

. Serial No. 650,050

14 Claims. (Cl. 149- 6) This invention relates to theimpregnation of A further object of the invention is to impregleather and more particularly to ya method of hate the leather with a substance that will be impregnating leather with compositionscontainretained by the fibrestructure when once deing materials obtained by polymerizing unsatuposited on same and not give rise tothe underated hydrocarbons and includes methods of maksired bloom characteristic of foils. and fats 5 ing and using the compositions and the products which on hydrolysis liberate stearic acid. v

" resulting from treatment with these composi- Another object of this invention is to provide tions. a compositionifor waterproofln'g leather and the The materials are of 800 to 2000 or, higher molike, which composition freely penetrates rand lecular weight (as determined by the viscosity thoroughly permeates the leather and the like and 10 method described in H. Staudinger's book, Die is stable on exposure, has a preservative action Hochmolekularen Organischem Verbindungen, on the leather and serves to protect it against 1932, p. 56), are excellent lubricants'possessing a injurious effects of wetting and drying in service high viscosity and are soluble in mineral oils. and at the same time maintaining the required 15 They are obtained. by polymerizing isobutylene. grade of plasticity of the compound throughout 15 The polymerization of. isobutyleneis conducted a'wide range of temperatures. at temperatures below 10'- C. with volatile Other objects will be apparent from the dehalide catalysts such as boron fluoride and hyscription of the materials used, the final product drogen chloride, though higher temperatures and and the method of production.

2 other catalysts may also be used such as mer- These and other objects of. the inventionwill cury chloride, tin foil, benzoyl peroxide, etc, be understood from the following examples Prior to the tanning operation in the manufacgiven; p ture of leather it is necessary to thoroughly re- .1 In the case of light coloredupper leather move the natural animal fats and oils contained made from calfskimit is preferable tointroduce in the original hide. The resulting product bethe material mixed with other oils and greases 25 comes harsh and brittle on drying and in order in the form of an emulsion in the so-called fat therefore to retain the desirable properties char liquoring operation. A suitable mixture of this acteristic of leather,- it is impregnated in a suitnature may be made up of the following:

able manner with oils and fats. Ordinary upper Percent leather and other types of light flexible products Polymer 2-10 30 are usually loaded with a certain percentage of Oil soluble sulfonate soap 10-15 oily material by drumming them with an emul- Neats foot oil 25 sion containing such constituents as neats foot Mineral oil of suitable viscosity such as 110 011, castor oil, fish oil, etc. with or without added seconds Saybolt viscosity at 100 F 50-63 mineral oil. Sole leather on the other hand is T] i usually loaded to a much larger extent by soaka fi fiff i j ggg zfgfifijg ordinary ing it in a molten bath of a mixture of paraffln g g 2. Side leather (split kip and the like) is treatwax and stearic acid with or without other ma- 7 teflals added to it ed with a mixture of the following composition.

40 The fatty and oily materials introduced lubri- 'Per cent 0 p cate the fibre bundles of the leather structure Polymer 2-10 in such a manner as to permit them to slide Oil soluble sulfonate soap 10-15 against each other and in between each other. Castor oil 25 This increases the flexibility of the product and Mineral oil of suitable viscosity 50-63 at the same time nourishes the leather so as to prevent it from becoming harsh and brittle These give compositions of substantially the with time. Many attempts have been made to proper consistency and have high penetration introduce rubber in some form or other to augcharacteristics- The polymers in these forms ment the effect of the fatty and oily constituents freely permeate the leather and like material mentioned above but eflort in this direction without being filtered out and left on the surface. 50 have largely been unsuccessful, Other suitable leather conditioning oils such as An object of this invention is to impregnate neats foot 011 may be substituted for the castor the leather with a substance which will lubricate 011 in the a e compositionand. at the same time not impart a greasy ap- 3. Sole leather is best impregnated by soaking pearance and feel to the finished leather. it in a molten bath of paramn wax, stearic acid, 5

etc. containing the polymer. A suitable mixture I of this material is made up as follows:

r Per .cent Polymer; l0 Stearic acid 40 Paramn wax -ito give a blend whose application conforms to good tannery practice.

In like manner. upholstery leather. glove leather, etc., may be impregnated in whatever manner fits best in the ordinary tannery practice. To increase the life and appearance'of upholstery leather. suitcases and otherarticles of this general time. the polymers may be applied to the surface at intervals. preferably dissolved in a light mineral 'oil carrier or emulsified in known manner, which makes for thorough. penetration. They may also be incorporated in the coatings applied to the surface of leather in the so-called finishing operation. in which case they act to a certain extent as plasticizers.

These polymers are eifective when used in ratherlow concentrations. and this'is important in the case of upper leather and other light products which to a large extent are colored with aniline dyes, the general experience being that such dyes'do not take properly to leather which contains even a moderate amount of ordinary mineral, vegetable or ofls and greases.-

' Tanned leather that has been treated with various salts such as sodium sulfate. barium chloride. magnesium sulfate, aluminum sulfate, etc., for floading" or other may likewise be im- Dregnatedwith solutions containing polymers of unsaturated hydrocarbons. The sulfonatesoaps used maybe prepared by neutralizing either a mineral oil jsulfonic acid or sulfonated fatty oils such as neat's foot oil, castor oll, etc.

and alternative compositions may be madewithinfthe scope of the .appended claims in which it 'ing toclaim l. in which castor oil is incorporated.

4. The method of treating leather, which comprism impregnating the leather with a composi- 7 tion containing a polymer obtained by polymerl zation of unsaturated hydrocarbons.

5. Method according to claim 4.-ln which the polymer is of 800 to 1500 molecular weight.

- 6. The method of treating-leather according to claim 4. in which the polnner is over lfiilil molecumwemm. g 7. The methodof treating leather. which'com prises impregnating the-leather with a composition containing a polymer'obtainedby polymerisation of unsaturated hydrocarbons, oil soluble.

'sulfonate soap, neat's foot oil and mineral oil.

8. An article of manufacture. comprising a leather and a high molecular weight polymer of an unsaturated hydrocarbon incorporated in said leather.

9. An article of manufacture, comprising 1a leather and a high molecular weight polymer of isobutylene incorporated in said leather. 10. The method of treating leather. which comprises impregnating the leather with a composition,containing a polymer obtained bypoly'mer'ization of unsaturated'hydrocarbons, oil-soluble sulfonate soap. and mineral oil.

11. Die method of treating leather. which cornprises impregnating the leather with a composi tion containing a polymer obtained by polymer isation' of; unsaturated hydrocarbons. and wax.

12. An article of manufacture. comprising a leather having incorporated therein both a high molecular'weight polymer of an unsaturated hydrocarbon.andneat'sfootoil. I f

13. An article of manufacture, comprisinga leather having incorporated therein both a high.

molecular weight polymer of an unsaturated hydrocarbon. and castor oil.

- 14. An article of manufacture. comprising a leather'having incorporated therein both ahigh molecular weight polymer of an unsaturated hy'-" drocarbon, and a wax.

- PEEK. FROLICH. 

